Add static icons for manga sources in drawer

app/src/main/java/org/koitharu/kotatsu/main/ui/MainActivity.kt

@@ -308,6 +308,7 @@ class MainActivity : BaseActivity<ActivityMainBinding>(),
 		submenu.removeGroup(R.id.group_remote_sources)
 		remoteSources.forEachIndexed { index, source ->
 			submenu.add(R.id.group_remote_sources, source.ordinal, index, source.title)
+				.setIcon(R.drawable.ic_manga_source)
 		}
 		submenu.setGroupCheckable(R.id.group_remote_sources, true, true)
 	}

app/src/main/res/drawable/ic_manga_source.xml

@@ -0,0 +1,11 @@
+<vector
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	android:width="24dp"
+	android:height="24dp"
+	android:tint="?attr/colorControlNormal"
+	android:viewportWidth="24"
+	android:viewportHeight="24">
+	<path
+		android:fillColor="#000"
+		android:pathData="M4 20H18V22H4C2.9 22 2 21.1 2 20V6H4V20M22 4V16C22 17.1 21.1 18 20 18H8C6.9 18 6 17.1 6 16V4C6 2.9 6.9 2 8 2H20C21.1 2 22 2.9 22 4M20 4H8V16H20V4M18 6H13V13L15.5 11.5L18 13V6Z" />
+</vector>